'Fringe' Season 5 teaser: Walter puts up a fight

The latest teaser for the final season of
"Fringe" opens with an idyllic scene in a park, with Peter (
Joshua Jackson) wishing his time with Olivia (
Anna Torv) would never end.

As we know from the
previous promo, though, it does end -- badly -- when a phalanx of Observers comes marching into view and sets sights on Peter and Olivia's daughter, Etta.

The new teaser inflicts further trauma on the Bishops. After a series of quick cuts that shows a giant Observer propaganda poster that reads "The future in order" and an ominous-looking medical lab, we see an Observer standing over Walter (
John Noble), who's tied to a chair and bleeding.

"You are fighting much more than I would have thought possible," the Observer tells him. Which sounds like a compliment on paper, but when spoken seems to portend some very bad things ahead for Walter.